What is "Start" and "Start Debugging" are needed in SSDT project?

Question

Hi,
I can not get why do I SSDT has Start With/without Debugging button. I can understand why is it needed when I am debugging stored procedure or T-SQL code. However I can click on that for the project. It builds it, implements changes to the database, doing
something else ... What is the difference with publishing?

Answer 1

Hi Sidukas,
Mostly it is used for smoke testing
Starting With Debugging
When you press F5 (Start Debugging) in Visual Studio it launches your application, attaches the Debugger, and let's you do all the "normal" things you would expect: 
The Visual Studio debugger is a powerful tool that allows you to observe the run-time behavior of your program and locate logic errors. The debugger works with all Visual Studio programming languages and their associated libraries. With the debugger, you can
break, or suspend, execution of your program to examine your code, evaluate and edit variables in your program, view registers, see the instructions created from your source code, and view the memory space used by your application. With Edit and Continue,
you can make changes to your code while debugging, and then continue execution.
The Visual Studio debugger provides a Debug menu for access to debugger tools. Debugger windows and dialog boxes display information about your program and enable you to enter additional information. You can obtain Help on any window or dialog box by pressing
F1.
Start Without Debugging
This is exactly what it sounds like.  It starts the application WITHOUT THE DEBUGGER ATTACHED.  That's it!  Nothing else.  It just doesn't attach the Debugger.  Otherwise everything else is the same.  So, the practical implications
of this are obvious:  Without the Debugger attached when the application runs it will not hit Breakpoints, emit Debug messages, etc.  So now let's deal with the biggest myth about Start Without Debugging.
 Myth:  Start Without Debugging Creates a Release Build
Nope.  It uses the build you are currently on.  So if you are using a Debug build and you press CTRL + F5 then it will run that Debug build.  The easiest way to test this is to use conditional compilation to see if you are using a Debug build:
Finally
Okay, so the obvious question is "Why?".  I mean, why would they give us this option?  Well the most obvious answer is so we can run the application without having to hassle with disabling breakpoints, etc. to do a quick "Smoke Test"
and see if it runs.  There may be other reasons you have for wanting to run without the Debugger attached as well.  So now you have a better idea of the difference between Start With and Start Without Debugging.  Go forth and debug away!